Automatic throttle control for multiengined aircraft



Sept. 16, 1941. M. F. BATES 2,255,753

AUTOMATIC THROTTLE con-m1. FOB mummnemsn AIRCRAFT Filed Nov, 17, 1939 2 Sheets-Sheet 1 f Az omqzv. I

Sept. 16, 1941. M. F. BATES 2,255,753

AUTOMATIC THROTTLE common FOR MULTIENGINED AIRCRAFT Filed Nov. 17, 19:59 2 Sheets-Sheet 2 INVENTOR Z ?;J Mllllllilllillllllllllli 27 .Z ZbrififlenZ'Bakg Patented Sept. 16, 1941 AUTOMATIC THROTTLE CONTROL FOR MULTIENGINED AIRCRAFT Mortimer F. Bates, Brooklyn, N. Y., assignor to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Application November 17, 1939, Serial No. 304,949

8 Claims.

This invention relates to means for seemin uniform performanceof combustion enginesin airplanes at different altitudes and has especial application to the supercharged type in which the best performance is secured by maintaining a uniform pressure at the intake manifold. I

One purpose of the invention is to provide an automatic means for maintaining the manifold pressure constant by automatically controlling the throttle opening.

Another object is to readily synchronize the speed of the several engines of a multi-engined craft by predetermined settings of the manifold pressure of each.

Other objects of the invention will become apparent from the following description,

Referring to the drawings,

Fig. 1 is a vertical section, partly in elevation, of my engine manifold pressure regulator.

Fig. 2 is a side elevation of the same as con structed for two engines, with the casing broken away to show theinterior. I

Fig. 3 is a horizontal section taken approximately on broken line 3--3 of Fig. 2.

Fig. 4 is a top view of the setting dial, showing graduations thereon in pounds per square inch (absolute).

Fig. 5 is a simplified wiring diagram showing the motors and control-levers leading to the engine throttles.

,Fig. 6 is a horizontal detailed section taken approximately on broken line 66 of Fig. 1.

Fig. 7 is a simplified elevation, partly in section, of the pressure controlled contact means.

Fig. 8 is an elevational detail looking in the direction of the arrows 8, 8 of Fig. 2.

In order to obtain a regulator responsive to intake manifold pressure, I connect the intake manifold of the engine with theinterior of a sealed chamber or box I by means of a pipe 2 leading to the intake manifold of one of thesupercharged engines on the aircraft. Within said box I mount .an evacuated sealed sylphon or metal bellows 3 in which a spring is compressed by atmospheric pressure, and operating somewhat as an aneroid barometer, to rotate lever 4, pinned at 4 to the top of the bellows, about pivotal axis 5, 5'. This pivotal mounting is shown as obtained through the intermediary of a U-shaped bracket 8 to which the threaded inner end of the lever 4 is clamped by nut 9. Said bracket carries the aforesaid pivots or trunnions 5, 5' journaled in the brackets or ears 8, 6 projecting from the outer wall of the chamber I,

which has a circular raised part I0 fitting in circular opening H in the housing 1.

To maintain a gas-tight seal for the chamber I in spite of the projection of the lever A through the wall of the same, I have shown a sylphon or resilient bellows 41 secured around the opening in said wall and through which the reduced threaded end 48 of the rod 4 projects. This bel Extending from one side of said bracket 8 is an arm Ill carrying at its outer end a'transverse pin I forming nubs extending a short distance above and below the arm. Said pin is normally engaged at top and bottom by the inner surfaces of a pair of contact'arms l2, l3 pivoted at l4, ll, respectively, and resiliently held against said pin by a spring 48. The arms l2, iii are shown as counter-balanced by adjustable masses I9 and I9. Arms i2 and I3 carry contacts l1 and I5, respectively, which cooperate with opposing contacts l6 carried by a lug l6 mounted on U-shaped member 20. In the unoperated or normal position shown in the drawings, contacts I! and ii are both held out of engagement with contacts i6 due to the position assumed by ar'm l0 (Fig. 7). Upward movement of arm ill from this normal position is brought about by the collapse of bellows 3 under the influenceof an increase in manifold pressure. This movement forces arm I2 upwardly and due to the force exerted by spring 40, arm l3 also rises bringing contact l5 into abutting relation with the lower contact i6, contacts l1 and 16 at the same time being separated to a greater extent by the displacement of arm 12. Downward movement of arm Ill in a similar manner results in bringing contact l1 into abutting relation with the upper contact [6 and effects an increase in spacing between lower contact l6 and contact l5.

The arms l2 and i3 are shown as pivoted on U-shaped member 20, which in turn is slidably mounted for up and down adjustment by means of upper and lower shafts 2| and 2!" sliding through bearings 22 and 22'. The lower bearing is shown as provided with a. pin and slot connection 23 to the shaft 2| to prevent turning of the member 20. At its lower end, shaft 2| is shown as provided with a roller 24 resting on an inclined or cam surface 25 of a segmental disc 26. It will be readily apparent that if the disc is moved to the right in Fig. 2, forinstance, the

roller 24 and its, shaft 2| will be moved upwardly thereby moving member 20 and contacts l8 mounted thereon upwardly-and bringing upper contact it into engagement with contact ii.

In the wiring diagram (Fig. 5) it is seen that engagement of contacts l6 and I1 completes a a circuit from the positive pole of battery 50 through said contacts to one end of field 5| of reversible motor 42 and through this field and the armature to the negative pole of the battery.

-Motor 42 is thereby caused to move throttle rod 44, by means of pinion 52 and rack 53, in a direction to increase the engine throttle opening and ment with upper contact I6, thereby breaking the circuit and deenergizing motor 42. Displacement of disc 26 to the right results in increased manifold pressure. Similar displacement of disc 26 to the left results in decreased manifold pressure by causing a downward displacement of shaft 2 I and member 20 and the bringing of lower contact l6 into engagement with contact [5. A circuit is thereby completed from the positive pole of battery 50 through contacts l6 and is to field 5| of motor 42 and through this field and the armature to the negative pole of the battery. The energizing of field 5| causes motor 42 to run in the opposite direction to that caused by the energizing of field 5| so that throttle rod 44 is moved to decrease the throttle opening and thereby decrease the manifold pressure'and cause in the base of the instrument. Also fixed to said base is the back plate 34 which adjustably carries the disc 26 in an annular depression 42. The angular position of said disc may be adjusted in said plate to vary the sensitivity of the lateral adjustment by first loosening clamp screws 35 which clamp the upper beveled surface 36 of an outer clamp plate 31 against annular beveled surface 38 around the periphery of the segment. After loosening the clamp screws, the operator turns the small pinion 39 meshing with teeth 43 on the periphery of said disc 26 by a screw driver to adjust the disc in its new position, upon which the clamp screws are again tightened.v

The manifold pressure which is set by the two above described adjustments is maintained constant since variation of pressure causes engageoperating with contacts l5 and il' corresponding to contacts l5 and II, respectively. Thus, it is seen (Fig. 5) that engagement of contacts l6 and i1 completes a circuit through field 53 of motor 43' causing rotation in one direction while engagement of contacts I6 and I5 completes a circuit through field 53' causing the motor to run in the opposite direction, the throttleopening of the associated engine being varied accordingly. A spark suppression circuit consisting of resistance 54 and condenser 55 is bridged across contacts l6 and I1 and a similar circuit consisting of resistance 54 and condenser 55. is bridged across contacts 15 and I6. Spark suppression circuits are also bridged across contacts 15', I6 and II. By this means a uniform performance of both enginesis secured and much experimenting with the controls avoided. Independent adment of one of contacts It with either contact l5 or I! thereby through the described means effecting a compensating change of throttle setting.

25 and 25, the disc being providedboth with trol the setting of a double contactifi having a.

function similar to that of contact 16 and co-' both engines are throttled up and down uniform-V ly. The desired absolute intake manifold pressure for both enginesis shown on the dial Iil at the top of the casing], which dial is shown as mounted on a vertical shaft 62 which carries at its lower end a pinion 63 meshing with a small rack 64 secured to the back of the base plate 32. As many changes could be made inthe above construction and many apparently widely different embodiments of this invention could be made without departing from'the scope thereof,

it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not a limiting sense.

Having described my invention, what I claim and desire to secure by Letters Patent is: 1. In a throttle control for airplane engines, means responsive to the absolute-intake manifold pressure, an adjustable controller actuated therefrom, independent throttling positioning means remotely controlled by said controller to maintain 2. In a throttle control for multi-engined aircraft, means responsive to the absolute intake manifold pressure of each engine, adjustable controllers actuated from each by variations therein, remote throttle positioning means controlled by said controllers for positioning the throttles of the engines to maintain a constant manifold pressure at each engine, manual setting means for simultaneously altering the adjustment of all of said controllers, and setting means individualto each engine for causing said first setting means to equally vary the manifold pressure on all engines,

3. A throttle control for multi-engined aircraft as claimed in claim 2, in which said manual setting means is provided with additional means for varying the individual coritrollerpositions for similarly changing the pressure of all the engines.

. 4.- In a throttle control for airplan engines, means responsive to the absolute intak manifold pressure comprising a sealed, partially evacuated, biased, resilient container having a movable end wall, an enclosure for the same connected with the intake engine manifold, alever resting on said movable end wall and extending beyond said container, and a second metallic-bellows secured around the opening in said container for said lever and having its outer end wall attached to said lever, whereby an airtight seal is furnished for said enclosure.

5. In a throttle control for airplane engines, means responsive to the absolute intake manifold pressure comprising a sealed, partially evacuated, biased, resilient container having a mov-' able end wall, an enclosure for the same connected with the intake engine manifold, a reversible controller operated by the movements of said end wall for automatically varying the engine throttle, and manual means for independently adjusting said controller for varying the speed of the engine.

6. In a throttle control for multi-engined aircraft, means responsive to the intake manifold pressure of each engine comprising a sealed, partially evacuated, biased, resilient container haveach engine operated by movements of the end wall of the respective container, and a common means for equally and simultaneously-adjusting all controllers including manual means for independently varying the eflect of said common means on each controller, whereby means are provided for adjusting the speeds of all engines simultaneously and uniformly.

7. In a throttle control ior airplane engines, means responsive to absolute intake manifold pressure, adjustable contact means including a normally stationary contact and relatively movable contacts cooperative therewith, said movable contacts being positionable by said pressure responsive means, throttle positioning means controlled by said contact means for varying throttle opening to maintain a normally constant manifoldpressure, and means for manually adjusting said contact means to vary manifold pressure.

8. In a throttle control for multi-engined aircraft, means responsive to the absolute intake manifold pressure 01' each engine, a source of electric power, individual throttle positioning means controlled respectively by said pressure means, each including adjustable pressure responsive contact means and a reversible motor operated from said source under the control of said contact means, and manually operated adjusting means for said contact means for simultaneously varying the manifold pressure of all engines in a similar manner.

MORTIMER F. BATES. 

